The present invention relates to a transmission operating device, and more particularly, to a device for operating transmission that a push-pull control cable (hereinafter referred to as a cable) is employed as means for transmitting operational forces.
Nowadays, a cable-type device for operating transmission (hereinafter referred to as a device) has been employed as a means for remotely operating a transmission of a front-wheel-drive small automobile having a front engine, a rear-wheel-drive bus or truck having a front engine, a rear-wheel-drive bus or truck having a rear engine, and the like. There are advantages in the device that it is light and low-cost, and that position of installing the devide can be relatively freely selected.
In the device, as shown in FIG. 7, rods 51, 52 connected with two cables (not shown) are arranged such that the rods are paralleled each other. Moreover, the rods 51, 52 are respectively operated by a single change lever 53 respectively.
That is to say, selecting operation of a transmission is performed by pushing/pulling the rod 51 for selecting in the longitudinal direction. The pushing/pulling operation is performed by inclining a change lever 53 in the right and left directions (in the direction of arrow P or arrow Q). And moreover, shifting operation of the transmission is performed by pushing/pulling the rod 52 for shifting in the fore and back directions. The pushing/pulling operation is performed by inclining the change lever 53 in the fore and back direction (in the direction of arrow R or arrow S).
In the device shown in FIG. 7, the change lever 53 is connected with a frame via a ball joint 54. Furthermore, a pair of rods 51, 52 are slidably guided by means of guide pipes 55, 56, each of which has a base portion rotatably connected with a cable cap (not shown in the drawing) fixed to the frame (not shown in the drawing). A control cable for shifting is connected with the change lever 53 via one of rods 52, and a control cable for selecting is connected with a first arm 58 of a bell crank 57 via another rod 51.
The bell crank 57 is rotatably connected with the frame, and a second arm 59 of the bell crank 57 is connected with a shaft 61 so that the bell crank 57 can be rotated and can be allowed to move in the axial direction without moving the shaft 61. The shaft 61 is connected with a ball member 60 of a ball joint 54 of the change lever 53.
Generally, in case that two control cables arranged parallel to each other are pushed or pulled by inclining a change lever, extending in the direction perpendicular to the control cables, in the directions of fore, back, right or left, the following problem arises. That is to say, the control cable cam be directly pushed or pulled when the change lever is operated in the direction of extending of the control cable, i.e. in the fore or back direction (in the direction of arrow R or arrow S in FIG. 7). However, when the change lever is operated in the right or left direction, the direction of operational force must be changed by means of a mechanism for changing direction, such as the bell crank 57 or the like.
Accordingly a construction becomes complicated and large, moreover, higher working accuracy and materials having smaller coefficient of friction are required in order to reduce a resistance of sliding. Therefore, production cost rises higher.
An object of the present invention is to resolve the above described problems, and to provide a transmission operating device that a construction is very simple, a loss of transmitting force is small, and moreover, production cost is low.